Added right-click option to select MAV, ensured that waypoints get updated properly on switching MAV

Added not yet working version of logging / log replay, fixed ALL bugs in main window, enabled full persistence in main window and serial link.

Substantially bugfixed and improved deactivation/activation and persistence of widgets. A lot of testing of Google Earth view, only minor improvements

Fixed initial startup bugs, cleaned up the activation-deactivation of update timers. Added initial instructions for new users.

Significantly bugfixed persistence and link adding/removal. Not yet fully there, but getting closer to release

Ardupilot support, builds now cleanly on Windows. Fixed a bug where the application could crash if no system was connected.

Working on QGraphicsView-based local waypoints interface supporting drag-and-drop, commented code, fixed Google Maps interface, added mouse and SpinBox zoom to HSIWidget, fixed MAV-based coloring and stylesheets - MEGA COMMIT

Cleaned up and commented major code parts. Refactoring HDD and HSI widgets to support QGraphicsView drag-and-drop, tested multi-MAV support more intensely, currently adding the system coloring to all widgets

Major cleanup of MainWindow constructor. All widgets have now the visible property set to false on its constructor